METHOD OF HOLLOW STEPPED PART MANUFACTURING Russian patent published in 2009 - IPC B21K21/08 

FIELD: technological processes, metal processing.

SUBSTANCE: invention concerns metal processing by pressure and can be applied in manufacturing of parts with stepped hollow space consisting of lesser diametre space with transition ledge and flat bottom area. Hollow spaces are formed in several steps by puncheons of different diametre in original blank cut off of a rod. At the first step a hollow of larger diametre is formed by reverse expression with calibration by reduction. Next hollow is formed by reverse expression. A hollow located above the hollow of lesser diametre is formed by reverse expression and shaping of transition ledge of required shape and size. Further a hollow of smaller diametre is formed by reverse expression, its bottom shaped as a flat area. Transition ledge height over the bottom is maintained due to a metal volume lifted from the bottom by expression.

EFFECT: expanded technological capacities of the method, improved quality of finished articles, enhanced durability of technological equipment used.

2 cl, 4 dwg